To receive your gifts in time for Christmas - please order before 17 December

For international delivery - please order before 12 December

More Views

Gerastos Trilobites 25mm


Availability: Out of stock

Product Name Price
No options of this product are available.

Availability:Out of stock


Gerastos Trilobites 25mm is the average size of these amazing fossil trilobites from the Devonian period. The prehistoric undersea world of that period which is now the Sahara desert floor. The detail on these marine invertebrates, which are also marine arthropods's is quite spectacular, particularly under a lens. The cephalon is the head shield section and the glabella is the central part of the cephalon, which in this genera is highly inflated and covered with tubercles and postules, this is referred to as pustulose ornamentation. A superb feature of this particular genus of trilobite. Also note the segmented thorax, a feat of natural engineering and liken to a suit of armour, a perfect little prehistoric bug which has been brought to life with the Lab technicians skill using high tech mechanical equipment and arduous and patient work to reveal the great details. Read more below...

Genus: Gerastos granulosus also Proetus tuberculatus morocensis
Age: Paleozoic era, Devonian period, Eifelian stage 393 to 388 million years ago.
Origin: Hamar Laghdad formation in Djebel Issoumour, Alnif, Morocco, North Africa.

The Golden colour pyrite cube included in the illustration images is 1cm square.

Gerastos average measurement.
Height: 0.8 cm
Length: 2.5 cm
Width: 1.7 cm

Overall average measurement.
Height: 3 cm
Length: 4 cm
Width: 5 cm

Average weight: 55 g

security logo enforcing our security levels using SSL certificate and encrypted software for your protection100% Secure. 128-bit Encryption

Free UK delivery - Recorded/Signed-for

Worldwide delivery available

Certificate of authenticity included

For EU & ROW delivery estimates please add your item/s to the cart and enter your desired destination.




Gerastos trilobites 25mm the Gerastos granulosus sp. Also known as Proetus tuberculatus, this trilobite is known for its tuberculate cephalon (head), or small granulose tubercles on the cephalon, hence the trilobites specific genus is also easily identified by the inflated cephalon and large holochroal eyes and short cephalon genal spines. The Gerastos trilobites are members of the Proetida, this is the family of Proetidae dating from the Paleozoic era, the Devonian period approximately four hundred to three hundred and fifty million years ago. These little trilobites were among the last of the arthropods to become extinct in the Permian era, known as the great Permian extinction, approximately two hundred and fifty-two million years ago, when up to ninety percent of life became extinct. This was a cataclysmic global event soon to be followed by other extinction level events (see our blog posts for more detailed information) since the Ordovician trilobites had been in decline as types dropped away, like the Phacopidae at the end of the Devonian period, extinguishing the Phacopida lineage. These fabulous trilobites have been prepared on the original matrix or bedrock to expose their exoskeleton, this is the carapace of the invertebrate made of a chitin (chitin, consists of calcite and calcium phosphate mainly, in a protein lattice), in the fossil process this hard chitin carapace calcifies (absorption of minerals in the fossil bed), over time creating what we see today, the fossilised remains of the once extant marine bottom dweller. The Gerastos trilobites have a remarkable likeness to modern day woodlouse arthropod, a segmented body cover and numerous legs, which is how we view the trilobite anatomy today. Excellent imagery has been developed particularly from the Burgess shale showing soft body parts within the fossil rock. Finding soft body parts is an extremely rare occurrence. The Fossil Store continues fossil finding trips to North Africa collecting trilobites from our colleagues in the field and in laboratory workshops. Our long-term connections afford us the luxury of knowing what preparation has been carried out or rather what repairs have not been made to our specimens, thus enabling us to guarantee every trilobite we sell and issue documentation to guarantee the authentication of each. The process of fossil collecting in the whole region of southern Morocco in the low lying Atlas ranges, the ranges here erupt from the desert, the northern Sahara and climb toward middle Morocco, Marrakesh and further north to the Riff valley, Mediterranean North Africa, also on to the west coast again falling back into the Atlantic, the practice of the fossil diggers is to literally crack open the fossil bedding plain into smaller pieces of rock, the rock is gradually reduced into hand sized nodules or slightly larger and finally cracked open one last time, when a trilobite is found the nodule is fixed back together and off to the lab for more technical extraction using pneumatic equipment and micro sand air abrasive machinery, taking many patient hours to release the fossil arthropod of its prehistoric tomb. The experienced and sympathetic preparatory can occasionally extract from the matrix, fossil bedrock, a marvellous complete specimen, as the Gerastos and Proteus listed here. Phylum arthropoda, Class trilobita, Order proetida, Family proetidae described by Salter 1843.


Additional Information

Age Devonian
Origin Morocco